Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['5245', '7253', 'u', '3131', '7037', '5359']

5245, 7253, 21, 3131, 7037, 5359